The present invention relates to a system for creating building instructions and more particularly to a system for creating building instructions for a three dimensional cabling assembly for use in a larger assembly.
Design of network systems such as wire cables used for power or signals, plumbing fixtures and pipes, heating, ventilation and air conditioning, aircraft mechanical cabling, pneumatic tubes and the like heretofore generally has been manual. For the purpose of brevity the word cable is used hereinbelow to represent all such elements appropriate to varied environments, such as, but not limited to, wire for electrical systems, pipes for plumbing systems and tubes for pneumatic systems. Wire, pipe or tube lengths, for example, are conventionally determined or estimated by various methods including measuring string on a mock-up scale or life-sized physical model of a product or of a building or by digitizing engineering drawings.
Resulting computer generated or manually generated engineering drawings are symbolic, which is a disadvantage when designing a network. Such symbolic manufacturing drawings are usually not geometrically accurate nor are the dimensions accurate. The final engineering drawing used for building the assembly is symbolic, so the drawing does not resemble a cable and thus has limited value to assemblers. Even when orthogonal drawings are geometrically accurate, one view is inadequate for assembly purposes since only two of the three dimensions can be shown.
A distinction is made between cable assembly and cable installation. Assembly defines the process of building a cable itself. Installation occurs during the process of incorporating the cable assembly in a larger assembly.
One of the few tasks not manually performed has been the process of drafting symbolic engineering drawings by a computer aided design system. Even here, administrative data as well as geometric data needed for drafting is usually accumulated ab initio and manually for each drawing.
One of the tasks conventionally performed by hand has been collection of administrative (textual) data for the drawings.
As a result of the aforementioned factors, engineering drawings that teach assembly for development projects have usually been inadequate and frequently inaccurate.
U.S. Pat. No. 3,927,948 issued to Cox et al discloses a method and apparatus for aiding and designing structures, including constructing a working model roughly representative of the proposed structure. A working model is scanned to determine the geometric shapes and arrangements of various components. Such information is converted into electrical signals acceptable to a computer. The data is processed from the model scanning operation in accordance with preselected sets of programs to obtain a computer symbolic model of the proposed structure. The symbolic model is visually displayed and data defining the computer symbolic model is modified to obtain a computer facsimile model either by altering the working model, by altering the visually displayed computer symbolic model or by processing the data defining the computer symbolic model with data supplied from databases. The step in the aforementioned disclosure of constructing a working model is a limitation that can be very burdensome, costly and time consuming. Moreover, such physical models are relatively difficult to modify. The two dimensional drawings resulting from the aforementioned system are orthogonal views only.
U.S. Pat. No. 4,464,719 issued to Spellmann discloses a method of depicting piping items of a pipe specification file of a computer-dominated piping graphics system, off-line, irrespective of piping class and without duplication. The aforementioned system generates a portion of administrative data required for cable assembly. Unfortunately, however, it does not allow for pipe section lengths to be entered into a system and accumulated in a bill of materials. Accordingly, the appropriate amount of pipe cannot be ordered in advance nor can the cost of assembly be estimated accurately. Moreover, the system would be unsuitable for assembling instructions, as it would provide inadequate information such as the identification and location of pipe connectors. Graphics are not depicted by the aforementioned system, resulting in only limited usefulness to an assembler.
An article titled "Solid Modelling of Electrical Wires on a Computer Graphics Display Screen" by C. E. L. Jones et al, copyright Butterworth & Co. (publishers) Ltd., 1987, discloses a project funded by the British Government to investigate the use of solid models in the production of assembly planning drawings. The disclosure teaches a method of displaying cables in three dimensions, but does not describe a method of designing them.
It would be advantageous to provide a system to create building instructions for a three dimensional cabling assembly.
It would also be advantageous for such a system to design a three dimensional digital computer model of a three dimensional cabling assembly and of a larger assembly by using a three dimensional mechanical design system.
It would also be advantageous for such a system to select a three dimensional view of the model and to transfer it to a two dimensional representation while retaining aspect ratios of the cabling assembly.
Moreover, it would be advantageous for such a system to provide, in human readable and pictorial form, overall lengths of cable sections aligned with the cable sections themselves.
It would also be advantageous to provide a system that permits administrative data to be entered into a model with a two dimensional representation.